The object of the invention is an apparatus for manufacturing of multi-element rods of the tobacco industry.
This invention relates to an apparatus for manufacturing of multi-segment rods of the tobacco industry wherein rod-like elements are transferred between conveyors along which the principally cylindrical elements of which the multi-segment rods are manufactured are axially lengthwise conveyed. In this document, the term of rod-like elements is to be understood as among others tobacco segments, tobacco rods, filter segments, filter rods made of one kind of material, multi-element filter rods comprising filter segments, rods containing elements changing the articles' aroma or giving such aroma, multi-element filter rods comprising filter segments and elements changing the filtering properties of filter materials used, multi-element rods comprising both filter and non-filter segments, multi-segment articles with a reduced tobacco content as well as cigarettes with a single-segment or multi-segment filter tip stuck on. Whereas the rod-like elements may be cylindrical, may deviate from the cylindrical shape, and also may have undercuts or hollows on both front and circumferential surface.
In the tobacco industry, it is common to put rod-like elements together in continuous trains of alternately different or the same elements, whereas multi-element rods are manufactured from such trains. These may include non-filter and filter elements with different filtering properties or alternately non-filter, filter elements and tobacco rods. The continuous elements trains are wrapped with a band of a wrapping material, for example a paper wrapper, forming a continuous rod, and are subjected to further processing, whereas in the first place they are cut into the abovementioned rods with a repeatable sequence of components.
There is a demand on the part of the tobacco industry manufacturers to put the rod-like elements together without gaps between the elements or with precisely determined gaps.
A difficult and very significant problem when putting elements together without gaps is to meet the expectation that the rod-like elements are to be pushed together, generally placed next to one another, in a repeatable manner. The feeding in a repeatable manner is understood as placing the elements in such a way that the influence of accidental factors on the final position of elements in the elements train is eliminated. Undesirable effects which may be caused by accidental factors include the formation of accidental gaps between the elements or excessive squeezing of the elements and consequently the deformation of the elements, which affects the quality of finished products.
The rod-like elements trains being put together and conveyed axially lengthwise are frequently transferred between rod-like element conveying apparatuses. Rod-like element transferring apparatuses are known from the prior art. For example from the document EP 1 763 306 B1 an apparatus for transferring individual rod-like elements or groups of rod-like elements, in this case of filter segments, is known. From the created elements train a continuous rod is formed and is cut into individual rods. At the time of transferring of the elements, the gaps necessary for correct transferring of the rod-like elements between successive rotational elements in the form of wheels provided with lugs on the circumference are maintained between individual groups of elements, whereas the groups of rod-like elements or the individual rod-like elements are placed in notches between the lugs. In order to form a rod-like elements train without gaps on a forming tape behind the transferring apparatus, the transferring tape moves with a speed being smaller than the circumferential speed of the last rotational element of the transferring apparatus. In the course of transferring of the rod-like elements onto the tape, there is friction between the elements and the paper wrapper (generally the wrapping material) situated on the forming tape. As a result of this, the rod-like elements arranged on the paper wrapper are not arranged in a repeatable manner, may be excessively squeezed or accidental gaps between the elements may occur. The speed of the transferring tape is smaller than the circumferential speed of the last rotational element, so the elements delivered by the last of the transferring wheels are pushed to the previously delivered elements. The elements are transferred along the paper wrapper moving with the tape speed. The glue which is usually applied on the paper wrapper may make it difficult to move the elements and the glue may accumulate between the elements. The elements placed on the paper wrapper have their own paper wrapping, it happens that the paper wrapper of the transferred elements is wrongly stuck, which may affect the correctness of the final position of the transferred group and the repeatability of the situation of neighbouring elements from the successive groups relative to one another. The apparatus shown in the abovementioned document EP 1 763 306 B1 maintains constant distances between neighbouring rod-like elements or groups of rod-like elements on the entire rod-like element conveying path. The rod-like elements are pushed close to one another only when these elements are placed onto the paper wrapper on the forming tape. That document does not disclose a method for bringing neighbouring elements or groups of elements closer to one another at the time of transferring so as to reduce shifting of the elements relative to the paper wrapper, generally relative to the wrapping material.
The problem to be solved by this invention is to develop an improved apparatus for transferring rod-like elements between conveying apparatuses on a manufacturing machine, whereas such apparatus will make it possible to gradually reduce the distances between the rod-like elements or the groups of elements, which will allow delivering the rod-like elements to the output conveying apparatus more smoothly, and in addition the position of the neighbouring groups of rod-like elements or individual rod-like elements will reduce the necessity of movement of the rod-like elements relative to the wrapping material. Furthermore, the transferring wheels should be provided with lugs which will ensure that the transferring of rod-like elements or groups of elements between successive wheels of the transferring apparatus will take place in a delicate way so as to prevent damaging of the rod-like elements in the course of transferring.